1. Technical Field
The present invention relates generally to control system input apparatus and methods for making same. More particularly, the present invention relates to integration of electronic touch switches or sensors with shaped panels, such as decorative fascia and the like.
2. The Prior Art
Conventional electrical control panels typically comprise one or more mechanical or membrane switches installed on flat, or planar, panels having substantially uniform thickness and/or cross section. One known type of control panel includes one or more mechanical switches mounted on a flat panel having one or more apertures for accommodating the one or more mechanical switches. Such control panels are commonly used in connection with a wide variety of equipment, including industrial machines, automobile dashboards, and all sorts of consumer products. Another known type of control panel includes one or more membrane switches mounted on a substantially flat substrate and covered with a thin, flexible plastic overlay. The overlay helps to protect the underlying switches and circuitry from spills and moisture. The overlay also may incorporate a decorative design, such as a mimic of the switch layout mimic, thereon. Such control panels commonly are used in connection with exercise equipment (such as rowing machines and treadmills), gas pumps, and all sorts of other apparatus.
Certain disadvantages are inherent in the foregoing types of control panels. For example, the apertures inherent to mechanical switch panels provide a path for fluids and contaminants to enter the rear portion of the control panel, increasing the potential for short circuits and damage to components within the panel. Further, the mechanical switches themselves typically are assemblies of several individual parts which are subject to moisture or fluid intrusion. As such, mechanical switch panels are less than ideal for use in harsh environments, unless peripheral protective enclosures are provided. Such enclosures are costly, unsightly, and make the switch panel inconvenient to use.
Switch panels using membrane switches offer some protection to the elements by way of the flexible overlay. However, such overlays typically do not provide a complete barrier to moisture and fluids. Also, they are prone to damage resulting from ordinary use and cleaning. Further, they can become embrittled with age, particularly if used in harsh environments. The overlays can develop cracks, leading to failure of the moisture barrier.
Mechanical switches generally are substantially rigid devices best suited for mounting on a flat surface or substrate. Although the contact mechanism in a membrane switch is inherently somewhat flexible, the overall switch package is substantially rigid and best suited for mounting on a flat surface or substrate. Neither mechanical nor membrane switches are particularly well-suited for use with any panel shape other than flat. Though attempts have been made to use such conventional switches in connection with shaped panels, such as curved panels, such attempts typically have not yielded elegant solutions. It would be desirable to provide a switch panel having a free-form design whose contours are not limited to planar surfaces.